1. Field of the Invention
The present invention relates generally to cooling systems for V-shaped, forced air-cooled internal combustion engines, of the type employing a radial flow cooling fan mounted on the front of the crankcase. More particularly, it relates to an improved arrangement for the cooling air passageways in such an air-cooled engine, whereby the same amount of cooling air is supplied to the cylinders on opposite sides of the engine, with a minimum of attendant noise caused by the flowing airstream.
2. Description of the Prior Art
While in theory offering several advantages, radial flow cooling fans have not heretofore found acceptance as a means to supply a flow of cooling air to the cylinders of a V-shaped forced air-cooled engine. This has been primarily because of the difficulty in arranging the radial fan and the cooling air passageways so that the engine's cylinders will be cooled equally and sufficiently by the airstream. In addition, where efforts have been made to design cooling air passageway arrangements that can properly divide the flow of cooling air, the flowing airstream has generated levels of noise that are unacceptable for normal conditions of use.
Because of these difficulties, it is now common practice to supply cooling air to such engines by a conventional fan, arranged to direct a flow of air axially rearwardly over the engine. While this arrangement provides good air distribution, the resultant structure is usually unduly large and complicated.
There is thus need for an improved arrangement for providing cooling air to a V-shaped, forced air-cooled engine by use of a radial cooling fan, wherein the flow of air to the cylinders mounted on the two sides of the engine will be even, and resultant levels of noise caused by the moving airstream will be within acceptable limits. The present invention is intended to satisfy that need.